Structural cranes in use on various type of construction jobs, of course, are characterized by the ability to move objects not only vertically, but also to move them horizontally from a first to a second position. This requires that the crane body and the boom itself be easily pivotable between a variety of a combination of positions so that the object being lifted can be grasped from whatever position it is in and subsequently deposited at a second desired position. Such a result is also desirable in a toy crane attachment for a child's tricyce.
Attempts have been made over the years to provide various types of crane or lifting attachments for use with tricycles, but none have met with the success in duplicating crane features as does the present invention nor do they disclose the structure of the toy crane attachment of this invention.
Exemplary of two prior art structures are Ewers, U.S. Pat. No. 2,630,334, and Jackson, U.S. Pat. No. 3,222,034. Both show crane type devices that are attachable to the rear tricycle but neither show the particular combination of structural elements set forth in the present invention. While both show the use of crank-type mechanism together with a chain or line attached to a lifting hook, the Ewers main frame, in the form of an A-shaped bent piece of metal tubing which is secured to the cross step above the axle of the tricycle, is not easily raisable or lowerable since raising and lowering of that A-frame section requires removal of the seat.
In Jackson, the device shows a fixed boom or hoist member which can attach to the rear of a tricycle and the attachment procedure does not allow subsequent movement of the boom member but only permits a lift line to be cranked.
Stevens, U.S. Pat. No. 2,209,359, discloses a child's toy crane that will stand by itself. The crane includes a flat base member from which a plurality of feet can be swiveled out to support the crane. A vertical member is pivotally fastened to the base and a boom is hinged to the vertical member. The position of the boom can be controlled by a reel and line combination and in a similar fashion, the position of the lifting hook on the boom can be controlled by second reel and line combination fixed only to the boom.
Proctor, U.S. Pat. No. 2,843,360, and Pilot, U.S. Pat. No. 3,001,763, both show crane type structures that could be mounted to a wagon. Neither is pivotable in a horizontal direction although Proctor shows a vertically pivotable boom member. The boom in Pilot is hinged at the rear so that it can be bent forward into the wagon, out of the way when not being used.
Wormser et al, U.S. Pat. No. Des. 228,358; Chabot, U.S. Pat. No. 4,224,007, and Magnusson, U.S. Pat. No. Des. 267,100, relate to various types of toy excavators or shovels. Wormser et al shows a fixed back hoe type of play apparatus whereas Chabot and Magnusson both show play type back hoes or shovels with each having its seat and back hoe pivotably connected to a base member.
Finally, Morehead, U.S. Pat. No. 3,152,838, shows a dump truck attachment for a tricycle.